The present invention relates to improved cell carrier grids and, more particularly, to cell carrier grids coated with biologically active materials and to cell carrier grids designed and constructed to hold cells in a single focal plane for analysis. The present invention further relates to cell carrier grids which allow recovery of individual cells based upon the results of analyses conducted thereupon.
Because of the complex nature of biological systems, it is often desirable to conduct analyses on a specific sample to compare to normative values. For example, liver enzyme levels from a specific patient compared to normative values for the same enzyme may be used to diagnose diabetes.
Further, it is often desirable to assay cells taken from a specific organ or tissue in order to diagnose a condition in a patient. In some cases, a sample may contain a physiologically mixed population of cells, only a portion of which is to be analyzed. Machines such as a fluorescence activated cell sorter (FACS) were designed, in part, to overcome this problem. However, a FACS machine cannot reassay individual cells after sorting. This limitation precludes both kinetic studies of individual cells and recovery of individual cells after assay based upon assay results.
Therefore, a number of prior art devices were patented by Weinraub et al. to address some of these issues. (U.S. Pat. Nos. 4,729,949; 5,272,081; 5,310,674; and 5,506,141)
U.S. Pat. No. 4,729,949 teaches methods and apparatus for performing analyses on individual living cells. According to the teachings of this patent, individual cells are forced into holes in a grid so that each of the cells may be individually assayed and re-assayed. The teachings of this patent do not provide means for assuring that all cells are held in a single focal plane during their residence in the grid and subsequent assay. As a result, practice of the teachings of this patent introduces inaccuracy into the measurements. In addition, the grid taught by this patent is biologically inert.
U.S. Pat. No. 5,310,674 is similar except that it teaches an ordered array of holes of two different sizes so that sorting of cells by size into two subpopulations is theoretically feasible. Teachings of this patent do not explain why a large cell will not be retained in a small hole when suction is applied therethrough.
U.S. Pat. No.5,272,081 teaches identification and subculture of a selected subgroup of cells residing in a grid of the type taught in U.S. Pat. No. 4,729,949. Therefore, the same inherent drawbacks are present in the teachings of this patent.
U.S. Pat. No. 5,506,141 is similar to U.S. Pat. No. 4,729,949 except that it teaches that xe2x80x9cthe positions on the carrier of the holes are identifiable.xe2x80x9d
U.S. Pat. No. 4,772,540 to Deutsch et al. teaches a method of manufacture for a rigid grid resistant to mechanical distortion. Despite the added strength, grids produced according to the teachings of Deutsch do not hold cells in a single focal plane.
U.S. Pat. No. 6,103,479 issued to Taylor teaches coating of miniaturized cell arrays with biologically active compounds in conjunction with an apparatus for cell-based screening concerning the physiological response of the cells to the biologically active compounds. Teachings of this patent do not include keeping cells in a single focal plane to increase accuracy of analysis. Similarly, analysis and subsequent collection of individual cells based upon assay results is not taught by this patent.
U.S. Pat. No. 5,635,363 issued to Altman et al. teaches the use of multimeric MHC-antigen complexes to form a stable structure with T-cells. Teachings of this patent do not include binding and subsequent assay of individual T-cells in order to allow for the labeling, identification and separation of specific T cells.
There is thus a widely recognized need for, and it would be highly advantageous to have, cell carrier grids devoid of the above limitations.
According to one aspect of the present invention there is provided a cell carrier grid capable of containing and retaining individual living cells in an array of predefined discrete locations. The cell carrier grid comprises (a) a body that defines a first and a second outer surface, the body having an ordered array of holes therethrough, each of the holes communicating between the first outer surface and the second outer surface; (b) an organizational plan, the plan being applied to the positioning of the holes on the body such that a position of each of the holes is identifiable so that the holes form the array of predefined discrete locations. Each of the holes is sized to contain at least a portion of an individual living cell therewithin, in that each hole has: (i) a first cross section at the first outer surface of such dimensions that at least a portion of the individual living cell can pass through the first cross section without suffering substantial damage; (ii) a second cross section at a level intermediate between the first and the second outer surfaces of such dimensions that the individual living cell cannot pass through the second cross section; (iii) a height between the first outer surface and the level of the second cross section such that at least a portion of the individual living cell is containable within the hole, and the individual cell is retained therein. The body is designed and constructed such that the individual cells contained within the holes reside substantially in a single focal plane during analysis and accuracy of data collected from the individual cells within the holes is increased because the cells reside substantially in a single focal plane.
According to another aspect of the present invention there is provided a cell carrier grid capable of containing and retaining individual living cells in an array of predefined discrete locations, the cell carrier grid comprising; (a) a body that defines a first and a second outer surface, the body having an ordered array of holes therethrough, each of the holes communicating between the first outer surface and the second outer surface; (b) an organizational plan, the plan being applied to the positioning of the holes on the body such that a position of each of the holes is identifiable so that the holes form the array of predefined discrete locations; and (c) wherein each of the holes is sized to contain at least a portion of an individual living cell therewithin, in that each hole has (i) a first cross section at the first outer surface of such dimensions that at least a portion of the individual living cell can pass through the first cross section without suffering substantial damage; (ii) a second cross section at a level intermediate between the first and the second outer surfaces said second cross section being no greater in size than said first cross section; and (iii) a height between the first outer surface and the level of the second cross section such that at least a portion of the individual living cell is containable within the hole, and the individual cell is retained therein. The body is at least partially coated with a biologically active material.
According to yet another aspect of the present invention there is provided a cell carrier grid capable of containing and retaining individual living cells in an array of predefined discrete locations, the cell carrier grid comprising; (a) a body that defines a first and a second outer surface, the body having an ordered array of holes therethrough, each of the holes communicating between the first outer surface and the second outer surface; (b) an organizational plan, the plan being applied to the positioning of the holes on the body such that a position of each of the holes is identifiable so that the holes form the array of predefined discrete locations and (c) wherein each of the holes is sized to contain at least a portion of an individual living cell therewithin, in that each hole has (i) a first cross section at the first outer surface of such dimensions that at least a portion of the individual living cell can pass through the first cross section without suffering substantial damage; (ii) a second cross section at a level intermediate between the first and the second outer surfaces said second cross section being no greater in size than said first cross section; and (iii) a height between the first outer surface and the level of the second cross section such that at least a portion of the individual living cell is containable within the hole, and the individual cell is retained therein. The body is designed and constructed such that the individual cells contained within the holes are recoverable by a recovery device.
According to further features in preferred embodiments of the invention described below, the body is inherently rigid, such that the individual cells contained within the holes reside substantially in a single focal plane during analysis.
According to still further features in the described preferred embodiments the cell carrier grid of claim 1, wherein the body is supported by at least one support, such that the individual cells contained within the holes reside substantially in a single focal plane during analysis.
According to still further features in the described preferred embodiments the cell carrier grid further includes a holder designed and constructed to: (i) facilitate manipulation of the cell carrier grid; (ii) allow application of suction through the holes in the grid such that cells in suspension applied to the first outer surface of the grid tend to move towards and into the holes; and (iii) permit application and removal of is solutions to cells residing in the holes.
According to still further features in the described preferred embodiments the biologically active material includes at least one material selected from the group consisting of a protein, a carbohydrate, a nucleic acid, and a lipid.
According to still further features in the described preferred embodiments the protein is selected from the group consisting of an antibody, an antigen, biotin, avidin, streptavidin, an enzyme, a ligand, a receptor, a mitogen, a haptene, a multimeric MHC-antigen complex and a lectin.
According to still further features in the described preferred embodiments the nucleic acid is selected from the group consisting of DNA, RNA and derivatives thereof.
According to still further features in the described preferred embodiments the lipid is selected from the group consisting of Lysophosphatydilcholine (polar phospholipid) and OxLDL
According to still further features in the described preferred embodiments the biologically active material is used to coat the body at a location selected from the group consisting of within the holes and adjacent to the holes.
According to still further features in the described preferred embodiments the biologically active material comprises at least two separate biologically active materials, each of the at least two materials applied to a portion of the holes comprising the array of predefined discrete locations.
According to still further features in the described preferred embodiments at least 20% of the individual living cell contained within a hole extends beyond a plane defined by the first outer surface to render the cell recoverable by a recovery device.
According to still further features in the described preferred embodiments wherein at least 40% of the individual living cell contained within a hole extends beyond a plane defined by the first outer surface to render the cell recoverable by a recovery device.
According to still further features in the described preferred embodiments wherein at least 50% of the individual living cell contained within a hole extends beyond a plane defined by the first outer surface to render the cell recoverable by a recovery device.
The present invention successfully addresses the shortcomings of the presently known configurations by providing cell carrier grids which are coated with biologically active materials and cell carrier grids designed and constructed to hold cells in a single focal plane for analysis. The present invention further relates to cell carrier grids which allow recovery of individual cells based upon the results of analyses conducted thereupon.